This invention relates to the preparation and use of phenolic age resistors for polymers, both unsaturated and saturated. More particularly, it concerns compounds comprised of a disubstituted phenolic group attached at the para position to a carbon chain containing sulfur, a carbonyl group, and a carboxylic ester moiety.
The use of sulfur-containing hindered phenols is known, e.g., see Canadian Pat. No. 904,339; U.S. Pat. No. Re. 27,004 and U.S. Pat. No. 3,590,083 and British Pat. No. 1,396,469.
The art disclosing hindered phenols is extensive, including those containing carbonyl or ester groups, see e.g. Japanese Pat. No. 27,735/68, U.S. Pat. No. 3,753,943; U.S. Pat. No. 3,810,929, Japanese Pat. No. 0468/63; Rubber Chemistry and Technology, Vol. 46, No. 1, Pp. 96-105, March, 1973; U.S. Pat. No. 3,714,122 and Canadian Pat. No. 812,262.